Regularly clean out gutters and check downpipes are clear.
All brackets and fixings should be inspected to ensure they are secure and take remedial action as necessary.
Clean polyester powder coated surfaces regularly by washing the coating using a warm mild detergent (non-toxic) solution.
This should be done with a soft cloth/sponge. Under no circumstances, should abrasive cleaners etc. be used.
Mill finish goods will develop a natural aluminium oxide coating which is a hard protective layer so no further maintenance is necessary.